What does «entrepiernas» mean in Spanish?

Lower part of the thighs (ú. t. in sing.).

Examples of use in Spanish: "Debo cuidarme las entrepiernas al correr porque si no me lastimo".
Corresponding part of the pants.

Examples of use in Spanish: "Tienes una rotura en las entrepiernas del pantalón".
Pieces sewn in this part as reinforcement or patch.
Euphemism for the genital area of a person. Used in the singular.

Examples of use in Spanish: "Tuvo un fuerte golpe en la entrepierna".
To pass something by the crotch. That something is not caring, indifferent.

Examples of use in Spanish: "Me paso por la entrepierna tu opinión".