also: よっこらせ
interjection
heave-ho; alley-oop
An interjection uttered when exerting physical effort, such as lifting something heavy or standing up with strain. Casual and often used by older speakers.
よっこらしょ、と重い荷物を持ち上げた。
With a 'heave-ho,' he lifted the heavy luggage.
おじいさんは椅子から立ち上がるとき、「よっこらしょ」と言った。
The old man said 'yoisho' as he got up from the chair.
Another variant with the same meaning; よっこいしょ is perhaps the most standard form, while よっこらしょ adds a playful or emphatic 'ra' sound.
A sound-symbolic interjection; the exact origin is uncertain, but it likely developed as a natural vocalization accompanying physical exertion.