themes is a form of:

Theme



noun
1.
(A topic, a short melody used as the subject of a musical composition, short essay, groundwork melody recurring at intervals and with variations. -theme song a song repeated several times during a musical play or motion picture. It is often intended to set the mood of general dramatic general recognition) ផ្ទៃរឿង, អត្ថបទខ្លីៗ
Example: Theme song, the theme of a discussion.
2.
(បច្ចេកទេស) មូលបទ, អត្ថបទខ្លីៗ
ENGLISH MEANING
noun
1.
A subject or topic on which a person writes or speaks; a proposition for discussion or argument; a text.
2.
Discourse on a certain subject.
3.
A composition or essay required of a pupil.
4.
A noun or verb, not modified by inflections; also, that part of a noun or verb which remains unchanged (except by euphonic variations) in declension or conjugation; stem.
5.
That by means of which a thing is done; means; instrument.
6.
The leading subject of a composition or a movement.