contrary to one's wishes; not going as hoped
Describes situations or outcomes that do not turn out as one desires. Often used in formal or written contexts.
The plan ended up going contrary to our wishes.
short of money; in financial difficulty
Specifically refers to being strapped for cash or facing monetary hardship. Often used in the phrase 不如意の身.
I put off the trip because I was short of money.
不如意な結果を受け入れるしかなかった。
We had no choice but to accept the unfavorable outcome.
Although he was in financial difficulty, he continued his studies.
金欠 is a casual, everyday term for being out of money, whereas 不如意 is formal and somewhat literary.
From the Chinese-derived compound 不 (not) + 如意 (as one wishes). The financial sense likely developed from the idea of things not going as desired, narrowing to monetary lack.