Unless they're used in a discussion specifically about human biology, "male" and "female" can be assumed to refer to gender. The terminology isn't neatly separated, unfortunately.
It depends on context. A discussion about "female singers" would probably be referring to gender.
It's useful to have an adjective equivalent of "man" and "woman", so people use "male" and "female" to mean that. My main point isn't to establish one meaning as more common, but to point out that there's not one "correct" meaning. Terminology around sex and gender are not neatly divided and it's not always easily determined what meaning people are using.
> Male is the sex of an organism that produces the gamete (sex cell) known as sperm, which fuses with the larger female gamete, or ovum, in the process of fertilization.
> Female is the sex of an organism that produces the large non-motile ova (egg cells), the type of gamete (sex cell) that fuses with the male gamete during sexual reproduction.
