Of a medium size

A car of intermediate size.

Being the size of a twin bed.

Small enough to be eaten in one bite / (by extension) Broken down into small pieces that are individually easy to understand or manage

bite-sized

(idiomatic) To evaluate; to estimate or anticipate the magnitude, difficulty, or strength of something. / To wear a larger size of clothing.

(colloquial) Of a reasonably large size.

(colloquial) Comparatively small in size.

(US) The smallest size of women's clothing / (informal) A woman with a very low body mass index, especially such a fashion model

(idiomatic, slang, originally LGBT, sometimes derogatory) Someone who prefers sexual partners with large penises.