Antonyms of adj fortuitous

2 senses of fortuitous

Sense 1
causeless, fortuitous, uncaused -- (having no cause or apparent cause; "a causeless miracle"; "fortuitous encounters--strange accidents of fortune"; "we cannot regard artistic invention as...uncaused and unrelated to the times")

INDIRECT (VIA unintended) -> intended -- (resulting from one's intentions; "your intended trip abroad"; "an intended insult")

Sense 2
fortuitous -- (occurring by happy chance; "profits were enhanced by a fortuitous drop in the cost of raw materials")

INDIRECT (VIA fortunate) -> unfortunate -- (not favored by fortune; marked or accompanied by or resulting in ill fortune; "an unfortunate turn of events"; "an unfortunate decision"; "unfortunate investments"; "an unfortunate night for all concerned")

Similarity of adj fortuitous

2 senses of fortuitous

Sense 1
causeless, fortuitous, uncaused -- (having no cause or apparent cause; "a causeless miracle"; "fortuitous encounters--strange accidents of fortune"; "we cannot regard artistic invention as...uncaused and unrelated to the times")
       => unintended (vs. intended) -- (not deliberate)

Sense 2
fortuitous -- (occurring by happy chance; "profits were enhanced by a fortuitous drop in the cost of raw materials")
       => fortunate (vs. unfortunate) -- (having unexpected good fortune; "other, less fortunate, children died"; "a fortunate choice")