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to place on (something)
to give (someone) a ride; to give a lift; to pick up; to help on board
父親は娘を肩に乗っけた。
The father hoisted his daughter onto his shoulders.
目玉焼きを丼に乗っけて渡した。
The cook placed a fried egg on the rice bowl and handed it over.
寝てる猫の頭に、子供が冠を乗っけようとする。
The child tries to place a crown on the sleeping cat's head.