Relating to or involving an asymptote; approaching a limit without ever reaching it.
From 'asymptote' plus the adjective suffix '-ical', an archaic or emphatic form of 'asymptotic'.
This is the old-fashioned version of 'asymptotic'—it's rarely used anymore because mathematicians settled on 'asymptotic' as the standard term.
Complete word intelligence in one call. Free tier — 50 lookups/day.