Coarser

[kawr-ser, kohr-] /ˈkɔr sər, ˈkoʊr-/

adjective, Mathematics.
1.
of or relating to a topology on a topological space whose open sets are included among the open sets of a second specified topology on the space.
[kawrs, kohrs] /kɔrs, koʊrs/
adjective, coarser, coarsest.
1.
composed of relatively large parts or particles:
The beach had rough, coarse sand.
2.
lacking in fineness or delicacy of texture, structure, etc.:
The stiff, coarse fabric irritated her skin.
3.
harsh; grating.
4.
lacking delicacy, taste, or refinement; unpolished:
He had coarse manners but an absolutely first-rate mind.
5.
of inferior or faulty quality; common; base.
6.
vulgar; obscene; crude:
His coarse language angered us.
7.
(of metals) unrefined.
8.
(of a metal file) having the maximum commercial grade of coarseness.
/kɔːs/
adjective
1.
rough in texture, structure, etc; not fine: coarse sand
2.
lacking refinement or taste; indelicate; vulgar: coarse jokes
3.
of inferior quality; not pure or choice
4.
(of a metal) not refined
5.
(of a screw) having widely spaced threads
adj.

early 15c., cors “ordinary” (modern spelling is from late 16c.), probably adjectival use of noun cours (see course (n.)), originally referring to rough cloth for ordinary wear. Developed a sense of “rude” c.1500 and “obscene” by 1711. Perhaps related, via metathesis, to French gros, which had a similar sense development. Related: Coarsely; coarseness.