Obligation - Crossword Clue, Answer and Explanation

'obligation' is the definition.
(I know that obligation can be written as duty)

This is the entire clue.

(Other definitions for duty that I've seen before include "Levy - tax on imports" , "Service - tax - office" , "Not subject to customs tax" , "A tax; compulsory task" , "assignment" .)

I've seen this clue in the Universal, The Washington Post, the LA Times, the Evening Standard, The New York Times, The Independent, the USA Today, the Sydney Morning Herald, the Newsday, The Telegraph, The Mirror, The Star Tribune, The Sun, the Penny Press, The Guardian and the King Feature Syndicate.

'obligation' is the definition.
(I've seen this in another clue)

This is all the clue.

(Other definitions for onus that I've seen before include "'Responsibility, task or burden (4)'" , "Encumbrance" , "'Burden, load (4)'" , "Responsibilty" , "Liability" .)

I've seen this clue in the Universal, The Washington Post, the LA Times, the Evening Standard, The New York Times, The Independent, the USA Today, the Sydney Morning Herald, the Newsday, The Telegraph, The Mirror, The Star Tribune, The Sun, the Penny Press, The Guardian and the King Feature Syndicate.

'obligation' is the definition.
(I've seen this in another clue)

This is all the clue.

(Other definitions for need that I've seen before include "Rely on" , "''A friend in .... is a friend indeed''" , "Want - require(ment)" , "Shortage" , "state of distress" .)

I've seen this clue in the Universal, The Washington Post, the LA Times, the Evening Standard, The New York Times, The Independent, the USA Today, the Sydney Morning Herald, the Newsday, The Telegraph, The Mirror, The Star Tribune, The Sun, the Penny Press, The Guardian and the King Feature Syndicate.

Obligation (4)