degree

sickness / ill, sick

(slang) abnormal, mentally ill

serious, deep, heavy (topic), profound (change), weighty (matter)

seriousness

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

becoming more serious

become more serious