決まらない

isn't decided, isn't determined

→ 決まる
verb · informal, present tense Rare #39,933
isn't decided, isn't determined Can also mean that something is not determined by a particular factor.
JA: 旅行の日程がまだ決まらない。
EN: The travel schedule hasn't been decided yet.
Conjugation of 決まる
Indicative present
決まってる決まらない

でもねえこの子が決まらないのよね

But, you know, I just can’t decide on this one.

— 魔女の宅急便 (1989)

なかなか決まらない。

I just can't make up my mind.

レスリングは体格で決まらない

Wrestling isn't determined by physique.

— ダンガル きっと、つよくなる (2016)