Adjective

(en adjective)

Bound or obliged in law or equity; responsible; answerable.

The surety is liable for the debt of his principal.

* 1748 . David Hume. Enquiries concerning the human understanding and concerning the principles of moral. London: Oxford University Press, 1973. § 34.

The passion for philosophy, like that for religion, seems liable to this inconvenience

Exposed to a certain contingency or casualty, more or less probable.

Likely.

Someone is liable to slip on your icy sidewalk.

Adjective

(en adjective)

Required; obligatory; mandatory.

* 1827 , A. D. Jr., Edinburgh Medical and Surgical Journal , A. and C. Black, page 212:

They are entirely private concerns, established by individual teachers, and attendance upon them is no more compulsory than attendance on our dispensaries.

* 1996 , (Ugo Pagano), Democracy and Efficiency in the Economic Enterprise , page 73:

Some might agree that membership in the firm is perhaps more compulsory than membership in a municipality, but balk at applying the analogy to the nation.

* {{quote-magazine, date=2013-07-19, author=(Peter Wilby)

, volume=189, issue=6, page=30, magazine=(The Guardian Weekly) , title= Finland spreads word on schools , passage=Imagine a country where children do nothing but play until they start compulsory schooling at age seven. Then, without exception, they attend comprehensives until the age of 16. Charging school fees is illegal, and so is sorting pupils into ability groups by streaming or setting.}}

Having the power of compulsion; constraining.