sign
sign of the times something typical of the nature or quality of a particular period, typically something undesirable.
sign on the dotted line agree formally.
1921P. G. WodehouseIndiscretions of Archie I spoke to him as one old friend to another…and he sang a few bars from 'Rigoletto', and signed on the dotted line.
sign your own death warrant do something that ensures your own demise or downfall.
sign the pledge: seepledge.
signed, sealed, and delivered (or signed and sealed) formally and officially agreed and in effect.