ac·ti·nide 
(ăktə-nīd′)
(ăktə-nīd′)n.
Any of a series of chemically similar, radioactive elements with atomic numbers ranging from 89 (actinium) through 103 (lawrencium). Also called actinoid.
[ACTIN(IUM) + -IDE.]
- infraorder
- infrared
- infrared astronomy
- infrasonic
- infrasound
- infraspecific
- infrastructural
- infrastructure
- infrequence
- infrequency
- infrequent
- infrequently
- infringe
- infringement
- infringer
- infructescence
- in full cry
- in full swing
- in fun
- infundibular
- infundibulate
- infundibuliform
- infundibulum
- infuriate
- infuriatingly