fluid liquid; flowing
fluido liquid, gaseous; flowing; electrical current
There is a lot of overlap in the meanings, but the issue here is that one of most common meanings of English
fluid in general usage is "in a liquid state (as opposed to solid, gas or plasma)" whereas in Spanish
fluido is "in a liquid, gaseous or plasma state (as opposed to solid)".
occasional from time to time, not very often; for a specific occasion
ocasional temporary; chance; for a specific occasion
An
encuentro ocasional is a chance encounter (and probably happens only once).
eventual final; occurring inevitably after a long period
eventual sporadic; temporary; provisional; possible
A
trabajador eventual is a temporary worker (not one who eventually gets around to working).