a subject of discourse, discussion, meditation, or composition; topic

The need for world peace was the theme of the meeting.

a unifying or dominant idea, motif, etc., as in a work of art.

a short, informal essay, esp. a school composition.

Music .

a principal melodic subject in a musical composition.

a short melodic subject from which variations are developed.

Grammar . the element common to all or most of the forms of an inflectional paradigm, often consisting of a root with certain formative elements or modifications. Compare stem 1 ( def. 16 ) .

Linguistics . topic ( def. 4 ) .

Also, thema. an administrative division of the Byzantine Empire.

having a unifying theme

a theme restaurant decorated like a spaceship.

to provide with a theme.

noun

affair , argument , burden , business , case , head , keynote , leitmotif , line , matter , matter in hand , motif , motive , point , point at issue , problem , proposition , question , stuff , subject , text , thesis , thought , topic , article , description , dissertation , essay , exercise , exposition , manuscript , paper , report , statement , subject matter , base , root , stem , chorus , composition , discourse , focus , idea , image , leitmotiv , melody , message , motto , mythos , premise , refrain , song , topos , tune