warrant

[1]	guarantee , promise , assure , ensure/insure , answer for , be answerable for , certify , vouch for , underwrite , back up , uphold , stand by/behind
[2]	authorize , sanction , justify , explain , approve , verify , validate , permit , allow , provide/offer grounds/justification/cause/reason for , call for , necessitate , entitle , empower , excuse , license
[3]	justify
[4]	guarantee

[1]	authorization , sanction , reason , justification , approval , validation , licence , right , certification , entitlement , grounds , cause , rationale , basis , assurance , carte blanche , guarantee , pledge , security , charter , warranty
[2]	writ , stock warrant , stock-purchase warrant , order , affidavit , paper , document , credential , permit , entitlement , licence , permit , summons , subpoena , mandate , decree , fiat , edict , ukase
[3]	sanction , countenance , endorsement , indorsement , imprimatur
[4]	guarantee , warrantee , warranty