drum, beat, rouse, muster
鼓 centers on the drum as an instrument and the action of striking it: beating a drum, rousing energy, or mustering people together through rhythm.
鼓 combines 壴 (a drum on a stand) with 支 (a hand holding a stick), depicting a hand striking a drum. The modern form preserves this clear pictographic origin.
The left side 壴 looks like a drum on a stand with decorations, and the right side 支 is a hand holding a stick. Picture a hand beating the drum to rouse the troops.
For コ, imagine a small hand drum making a sharp 'ko' sound with each beat: ko -> コ, and the drum rouses everyone.
drum
beat; palpitation; pulsation; throbbing
encouragement; inspiration; rousing; stirring up; raising (e.g. morale)
hand drum
eardrum; tympanic membrane
large seal; large stamp
smacking one's lips (over food)
drum and fife band
war drum
pellet drum (used as a children's toy); rattle drum
beating of a drum as a signal to announce the opening (beginning) of an event (theatrical performance, festival, etc.)
the first beat of the war drum
hourglass drum used in Nara-period court music
the three types of gagaku drums
inferior tympanic artery
traditional toy rattle drum from Kagoshima
to screw up one's courage; to take heart
Japanese drum
dadaiko drum; large drum used for outdoor bugaku and gagaku performances
large drum; bass drum