noun
A wooden crosspiece fastened over the necks of two animals and attached to a plow or cart.
牛にくびきをかけて畑を耕した。
They yoked the oxen and plowed the field.
noun
constraints; oppression; shackles
Figurative use for something that restricts freedom, like a burden or oppressive force.
伝統のくびきから逃れたい。
I want to break free from the shackles of tradition.
Rarely used kanji form.
束縛 is a more common word for 'restraint' or 'restriction', while くびき is a literary metaphor for oppressive constraints.
The word is native Japanese. The kanji 軛 specifically means 'yoke', while other forms are variant spellings. The figurative sense developed from the physical yoke as a symbol of subjugation.