Readings & Meanings:
habit, custom, to get used to
I have slowly become accustomed to my new work.
I keep up the habit of "early to bed, early to rise."
Radical is 心 in its vertical form on the left.
貫 is the phonetic, which is a pictograph of two seashells connected by a string that goes through them both. The original meaning is "pierce," but "consistent" is the extended meaning, and the one that applies here.