Noun

(en noun)

Something that impedes, stands in the way of, or holds up progress

A big obstacle to understanding the manual was that it had been poorly translated from the Japanese.

Noun

(en noun)

The act of objecting.

* {{quote-magazine, date=2013-06-07, author= Ed Pilkington

, volume=188, issue=26, page=6, magazine=(The Guardian Weekly) , title= ‘Killer robots’ should be banned in advance, UN told , passage=In his submission to the UN, [Christof] Heyns points to the experience of drones. Unmanned aerial vehicles were intended initially only for surveillance, and their use for offensive purposes was prohibited, yet once strategists realised their perceived advantages as a means of carrying out targeted killings, all objections were swept out of the way.}}

A statement expressing opposition, or a reason or cause for expressing opposition (generally followed by the adposition to ).

(legal) An official protest raised in a court of law during a legal trial over a violation of the rules of the court by the opposing party.