bitter, catastrophic, complete, comprehensive, crushing, decisive, devastating, disastrous, heavy, humiliating, ignominious, overwhelming, resounding, serious, stunning
Their party suffered a heavy defeat in the election. | The battle ended in a humiliating defeat.

narrow
They lost 4-3 in their second narrow defeat of the week.

consecutive, successive | election, electoral, political | military

accept, admit, concede
She is very determined, and will never admit defeat. | The prime minister conceded defeat and resigned.

face | go down to, slump to, to suffer
The team went down to their fifth consecutive defeat.

reverse
A skilful politician can always reverse any defeats.

avoid
We just need to avoid defeat in our last two matches.

inflict
The army inflicted a heavy defeat on rebel forces.

end in | lead to

~ against
last week''s crushing defeat against Manchester United

~ by
their defeat by the French

defeat at the hands of sb
The team suffered defeat at the hands of their oldest rivals.

comprehensively, convincingly, decisively, easily, heavily, soundly, totally
The English were heavily defeated by the Scots in the battle that followed. | The proposed bill was decisively defeated in Parliament.

narrowly
Our team was narrowly defeated in the final.

eventually, finally, ultimately

by
The motion was defeated by 20 votes to 18.