plain dealer noun

A person who is candid and outspoken

plain dealing noun

plainˈ-dealing adjective

plain flour noun

Flour that is not mixed with a raising agent

plainˈ-heartˈed adjective

1. Having a plain or honest heart
2. Sincere

plainˈ-heartˈedness noun

plain Jane noun (derogatory informal)

A plain, dowdy girl

plainˈ-Jane adjective

1. Ordinary, unremarkable
2. Plain, esp of a garment

plain language noun

Straightforward, understandable language

plain loaf noun (Scot)

A batch loaf (qv under batch¹)

plain sailing noun

1. Sailing in open, unrestricted waters (nautical)
2. An easy, straightforward task, affair, etc (figurative)
3. See also plane sailing under plane¹

plainsˈman noun (pl plainsˈmen)

A dweller in a plain, esp in N America

plainˈsong noun

1. Unmeasured, unaccompanied music sung in unison in ecclesiastical modes from early times, and still in use in Roman Catholic and some Anglican churches
2. A simple melody
3. That to which a descant can be added

adjective (Shakespeare)

Singing a simple theme

plain speaking noun

Straightforwardness or bluntness of speech

plainˈ-spoken adjective

1. Plain, rough, and sincere
2. Frank, candid, esp if rather blunt

plainˈstanes plural noun (Scot)

Flagstones, pavement (also plainˈstones)

plain text noun (computing)

Text that is readable and uncoded

plain weave noun

A weave in which the weft is passed alternately under and over the warp

plainˈwork noun

Plain needlework, as distinguished from embroidery

plain as a pikestaff see under pike²