(US) To expend more money or effort in gaining something than it is worth.

(jargon) The practice of engaging in anal sex with the deliberate intention of contracting HIV.

(mathematics, somewhat informal) Proof in stages, each of which, in general, depends on the previous stages and can be visualized by means of a diagram of morphisms.

present participle of chase rainbows

(derogatory) The action of an ambulance chaser.

(slang) The practice of blowing large clouds of vapor using electronic cigarettes.

present participle of contour chase

present participle of ambulance-chase

present participle of chase the dragon

present participle of chase a rainbow