Depending upon the font used, elements are「person」with「rod with short hairs, tally」or「prick」with「reaming」「in two hands, large」that suggest a painful procedure with a bougie CARVING and SCRAPING the inside of the urethra in order to clean the gleet and reopen the passageway, causing one party in a relationship to PLEDGE, PROMISE, VOW to not CONTRACT the infection again, and there was only one way to do that in the good old days: MONOGAMY. In Western legal systems, marriage is also a legal contract, and not simply a religious experience.
　In Japan, also refers to CONJUGAL SEXUAL RELATIONS between spouses, perhaps as fulfilling their marriage PLEDGES, VOWS of MONOGAMY.
　Some suggest a piece of wood with the words of a pledge or promise carved onto each side (mutual promises between parties are what form a legal contract), cut in two parts with a zigzagged cut so that only the original two halves will reconnect perfectly to form the whole once again. Tallies were also cut with notches in order to count the fulfillment of a pledge they say, most often the repayment of a loan by the installment method. With either「two hands, big」meaning that the tallies of both sides have been given to two hands or joined together again by two hands upon fulfillment of the pledge into one (big) piece, one per party to the original contract.
　Today in Japan, the same action is achieved by each party to a contract pressing their personal seal (chop) over the crack where pages of a contract have been joined, making it nearly impossible in the past to replace a page with altered text…modern high resolution scanners can fool some folks at first glance though, and second or third glances, too.

Modern definitions (that generally disregard history) …excluding politically incorrect concepts and other meanings deemed offensive today; may list only pigeonholed definitions, euphemisms, or meaningless mnemonics)
Chinese: variant of 契; contract