mar (v.)
ruin, harm, injure, damage
AYL I.i.29 [Oliver to Orlando] What mar you then, sir? [make or mar = cause success or ruin]
AYL I.i.30 [Orlando to Oliver] I am helping you to mar that which God made
JC III.ii.198 [Antony to all, of Caesar] Here is himself, marred, as you see, with traitors
KL I.i.95 [Lear to Cordelia] Mend your speech a little / Lest you may mar your fortunes
Tem I.i.13 [Boatswain to Antonio] You mar our labour
TS IV.iii.113 [Petruchio to Tailor, of Katherina] thou hast marred her gown
TS IV.iii.97 [Petruchio to Tailor, of making a dress] I did not bid you mar it to the time
WT IV.iv.476 [Florizel to Perdita] Let Nature crush the sides o'th' earth together / And mar the seeds within!