A contractile muscular ring by which an orifice of the body (in people or animals) is normally kept closed.

Something which lifts or raises an object from one level to another. Also in extended use.

an internal muscle.

Anatomy. An oblique muscle (cf. A. 2c).

An abductor muscle; spec. the lateral rectus muscle of the eye. Also abducens muscle. Now rare.

Anatomy and Zoology. Any muscle that draws a part of the body away from the median plane or midline, or away from another part. Frequently attributive…

Any muscle that draws a part of the body towards the median plane or midline, or that brings two parts (such as the valves of a bivalve mollusc…

Physiology. A muscle that opposes the action of another muscle in producing movements of a specific part of the body. Cf. agonist, n. 4.

A flexor muscle. Obsolete.

Anatomy and Physiology. A muscle which depresses or pulls down the part to which it is attached; also attributive as depressor muscle.

Of a muscle; = extensor, n. Obsolete.

A muscle whose function it is to produce flexion in any part of the body. Opposed to extensor.

Anatomy. A muscle whose function is to raise the part to which it is attached = elevator, n. 1a; also attributive, as levator-muscle.

Any of various muscles that are more or less square in shape; esp. (a) (more fully quadratus lumborum) a muscle of the back that arises from the…

In humans and other vertebrates: any of various straight muscles (typically rectangular in shape and located parallel or perpendicular to the long…

Anatomy and Zoology. More fully retractor muscle. A muscle that serves to pull in a retractile body part, or to move a part downwards or backwards…

= 1.

Anatomy, Zoology, and Physiology. Originally: a muscle that accelerates a physiological process; (in early use) spec. the bulbospongiosus, a muscle…

A muscle with two heads or tendinous attachments; spec. that on the front of the upper arm, which bends the fore arm; also the corresponding muscle…

Anatomy. A muscle which raises or moves a limb or an organ.

Anatomy. = adductor, n. Obsolete.

Something which lifts or is used for lifting. Technical uses: †(a) Anatomy = levator, n. 2 (b) Mining. The wooden beams used as stems for stamps…

Anatomy and Zoology. More fully rotator muscle. Any muscle by which a limb, appendage, or other part of the body can be rotated. Also with…

= flexor, n.

One who or that which contracts, narrows, or shortens; used esp. of muscles which contract or draw in some part of the body.

Anatomy. A muscle which dilates or expands a part; = dilatator, n. a, dilator, n.1 b.

= orbicularis oculi, n.

any one of various muscles extending across other parts.

Anatomy. Also tensor muscle. A muscle that stretches or tightens some part. Opposed to laxator.

A muscle, distinguished by its two bellies or bulges; esp. the digastric muscle.

A muscle which serves to extend or straighten out any part of the body. Opposed to flexor.

A muscle of this kind.

Anatomy. A muscle which draws together or narrows a part. (Frequent in the Latin names of individual muscles.)

One who or that which dilates: spec. Anatomy. A muscle or nerve which dilates or widens a part; = dilatator, n. a, dilater, n. c. Also attributive.

In plural. Chiefly U.S. The risible faculties or muscles (see A. 2).

A muscle that encircles the orbit and passes through the eyelids, serving to close the eye. Also orbicularis oculi muscle.

More fully obliquus muscle. An oblique muscle. Also with distinguishing word.

A term applied to certain muscles, from their office in causing erection in any part of the body. Also attributive, as in erector-muscle.

attributive in extensor-muscle; also extensor-surface n. the surface of a bone to which the extensor muscles are attached.

One who or that which compresses: in technical uses. Anatomy. A muscle which compresses a part. (Frequent in the Latin names of individual muscles.)

A crossing or transverse muscle.

Physiology. A muscle that antagonizes another muscle; = antagonist, n. 3. Obsolete. rare.

Anatomy. A muscle that moves a part of the body.

Any muscle that turns a part outward; esp. the peroneus brevis or peroneus longus, which evert the foot. Also evertor muscle.

That which inflects or bends. (In quot. 1851 attributive.)

Zoology. A muscle whose contraction protracts or extends a limb or organ. Also more fully protractor muscle.

Physiology. = agonist, n. 4.

Anatomy. An orbicular muscle (see sense A. 3 and orbicularis, n.); esp. the orbicularis oculi. rare.

A transverse muscle; one of the muscles, etc., that lie across various parts.

Anatomy. Any muscle involved in inversion of the foot (see inversion, n. 22); esp. the tibialis posterior or tibialis anterior (see tibialis, adj.)…

a muscle attached to and controlling a part of a skeleton or transmitting force to connective tissue sheets, and in most cases under voluntary…

Anatomy. A muscle which dilates or expands a part; also attributive.

A muscle (or, rarely: other structure) that serves to close an opening or passage. Frequently attributive, esp. in occlusor muscle.

General attributive, as sphincter control, sphincter-fibre, sphincter-power.

A pilomotor nerve; an arrector pili muscle.

Physiology. A muscle that is in a state of contraction during the production of a specific movement. Also agonist muscle. Cf. antagonist, n. 3.