1 constitute, form, make (up), be a constituent or ingredient or component or element of, be a part of:
Clouds are composed of countless particles of water.
2 write, create, imagine, think up, originate, frame, formulate, make (up), author, devise; contrive; set to music, arrange:
He composed the poem while travelling on the Flying Scotsman. That symphony was composed in 1873.
3 be composed of. consist of or in, comprise, be formed or made (up) of, be constituted of:
The new government is composed of a coalition of three parties.
4 compose oneself. calm (down), quiet or quieten (down), pacify, control oneself, get control of or over oneself:
They stopped crying and composed themselves.