thing vs whacker

thing and whacker both are nouns.

Word	Noun	Adjective	Verb	Adverb
thing	Yes	No	No	No
whacker	Yes	No	No	No

As nouns, whacker is a hyponym of thing; that is, whacker is a word with a more specific, narrower meaning than thing:

thing (noun)	whacker (noun)
a separate and self-contained entity	something especially big or impressive of its kind
an action
an artifact
an entity that is not named specifically
any attribute or quality considered as having its own existence
a special abstraction
a special objective
a vaguely specified concern
a statement regarded as an object
an event
a persistent illogical feeling of desire or aversion
a special situation