(mathematics) pure mathematics

enthusiasm, passion

pure, unmixed, genuine / selfless, pure / innocent

purity / selflessness, purity / innocence

pour into, fill / sprinkle on, water something / concentrate effort, focus energy / for rain or snow to fall

pour into something / serve food, dish out food, fill a container with food

mathematics (field of study)

he / distal demonstrative, something far off removed from both speaker and listener: that / boyfriend

distal demonstrative, something far off removed from both speaker and listener: that, yon / particularly, male personal third person pronoun: he / by extension from he: boyfriend

he; boyfriend