"'chomp' means to chew noisily (according to dictionaries)"

While 'chew noisily' is one meaning that's still in common use, another is something on the order of 'bite down hard.' Chomp is often uttered with the intent to evoke the action of very large teeth seizing or biting off part of some target entity... such as a piece of steak or -- in a figurative sense -- a target's posterior, in the course of excoriating the target's failure to perform to some standard. From there, it's not to hard (for me, YMMV) to associate the name with removal of a trailing (and often 'useless' or'un-acceptable') newline.

And re eyepopslikeamosquito's comment on "(c)arp module function names: carp, croak, confess and cluck":

• 'Carp's utility seems to me to match the standard definition of the name itself -- to complain about something, sometimes in a petty manner.
• 'croak' can be used as slang for 'die.'
• 'confess' seems self-evident (but maybe my mind has been twisted by too much etymology).
• 'cluck' -- an onomatopoetic word for the sound of a contented hen -- is also, at least in NE US-ian slang -- used to mean 'remonstrate' (and often used in the context of a sexist, age-ist remark involving an elderly female -- 'old hen' in the same slang).

Now, were any of the above even considered in naming the Perl functions? I can't say, but the associations seem suggestive.