malapropos

adjectives

of an inappropriate or incorrectly applied nature
antonym
is similar to
of an inappropriate or misapplied nature
see also
not suitable for a particular occasion etc
"noise seems inappropriate at a time of sadness"; "inappropriate shoes for a walk on the beach"; "put inappropriate pressure on them"
is an attribute of
the quality of being specially suitable

adverbs

at an inconvenient time
"he arrived inopportunely just as we sat down for dinner"; "she answered malapropos"