Of uncertain origin, this term often connotes extreme
frustration. The general consensus is that it originates from the
Army (the source of many creative Singlishphrases), where a
"spider" was dirt in the barrel of one's rifle. If during
inspection, you found a "spider" in your rifle, you'd have to strip
it and clean it all over again. Hence, "fuck spider" would either
be a common expletive amongst recruits, or an exhortation by an
annoyed inspecting officer/NCO. Some, however, believe itdates back
to an old practice amongst boys to catch spiders in the
undergrowth, house them in small boxes and make them
fight.