(malacology) callus

total concentration in something, being totally absorbed insomething

immersing oneself in something completely, totally absorbing oneself in something

layer upon layer; level by level; multi-layered

slippery / slip / flunk / slide

smooth thing, slippery thing / in mountaineering, the place where a little water is running on a smooth rock

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

to research, to study