to lock (a door, etc.) / (Internet slang) (of a SNS account) to change privacy setting to limited people and posts and/or profiles can be seen by limited people.

to be concerned about, to worry about / to weigh on one's mind

pivot word (a form of punning in traditional Japanese poetry)

(more emphatic) Alternative form of かける (kakeru, “to pour onto, to shake onto, to splash, to drip”): to pour/shake/splash vigorously

掛け算: (arithmetic) multiplication

calling out to someone

(idiomatic) to curb, to halt, to put an end to

running / (figuratively) being hurried; hurrying

(equestrianism); to run

one's personal thoughts