Definition of "restrained"

Ha? fie, these filthy vices. It were as good To pardon him, that hath from nature stolne a man already made, as to remit Their sawcie sweetnes, that do coyne heauens Image In stamps that are forbid: 'tis all as easie, Falsely to take away a life true made, As to put mettle in restrained meanes To make a false one.

c. 1603–1604 (date written), William Shakespeare, “Measure for Measure”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, [Act II, scene iv], page 69, columns 1-2