Synonyms of improvised in English:

improvised


See definition of improvise

adjective

1‘an improvised short speech’

SYNONYMS
impromptu, improvisational, improvisatory, unrehearsed, unprepared, unscripted, extempore, extemporized, spontaneous, unstudied, unpremeditated, unarranged, unplanned, on the spot, ad lib
ad libitum
informal off-the-cuff, spur of the moment
rare improvisatorial
ANTONYMS

prepared, rehearsed

2‘an improvised shelter’

SYNONYMS
makeshift, thrown together, cobbled together, devised, rigged, jury-rigged, rough and ready, make-do, emergency, stopgap, temporary, short-term, pro tem
ad hoc, pro tempore, ad interim