transitive. To think about, turn one's attention to (an activity or task); to direct or apply oneself to, bring one's mind or energies to bear…

transitive. To turn one's thoughts to, fix the mind on (something); to attend to; to occupy oneself with; to look after. Obsolete.

intransitive. To have as one's business or concern; to give consideration to; to manage, administer.

transitive. To take up or develop (an activity, habit, interest, etc.), esp. for the purpose of self-improvement.