1) Discriminate 2) Know apart 3) Make more keen 4) Make more subtle or refined 5) To make less gross or coarse 6) To make subtle 7) To make thin or fine 8) To refine 9) To spin into niceties 1) Subtilise 
• (v. t.) To make thin or fine; to make less gross or coarse. • (v. i.) To refine in argument; to make very nice distinctions. • (v. t.) To refine; to spin into niceties; as, to subtilize arguments.
Sub'til·ize transitive verb [ imperfect & past participle Subtilized ; present participle & verbal noun Subtilizing .] [ Latin subtiliser .] 1. To make thin or fine; to make less gross or coarse. 2. To refine; to...
[v] - mark fine distinctions and subtleties, as among words 2. [v] - make more keen, as of the senses
verb make more subtle or refined