Given an entity as input, output another entity which is part of the input entity. These are entities of meronym. In linguistics, meronymy is a semantic relation between a meronym denoting a part and a holonym denoting a whole. In simpler terms, a meronym (i.e., output entity) is in a part-of relationship with its holonym (i.e., input entity).

[Q]: central cavity
[A]: marrow


[Q]: bear - blue flower
[A]: minute petal


[Q]: ground - level ozone pollution
[A]:
nitric oxide