main, principal, important

a division / something that divides two objects

heavy, weighty / involving large-scale manufacture, heavy / great in degree, heavy, serious, severe, hard, difficult

the number of overlaps; fold, layer

weight

to use one's head

use one thing for many purposes / work someone hard

a chain with a weight on one or both ends, such as might be used on a pulley to help lift loads / (weaponry) a Japanese martial arts chain weapon, consisting of or based on such a weighted chain

a 家紋 (kamon, “family crest”) in the shape of a 桜 (sakura, “cherry blossom”), with each petal depicted using the shape of a 分銅 (fundō, “weight for a scale”)

not in the mood to do things; having a heavy mood