購入|こうにゅうkounyuu[0]heiban (flat)

1. noun, suru verb, transitive verbpurchase; buying
   チケット購入こうにゅうに必要ひつような個人情報こじんじょうほうをインプットする。↗

   To purchase a ticket, you need to enter your personal details.

• Synonym買い込むかいこむCasualColloquial: to buy up in quantity and stock it away, as in 「食料を買い込む」. It stresses how much is bought, which 購入 does not — 購入 simply states the act of buying.
• Synonym買い上げるかいあげるFormalFormal: a government or public body buying from private parties, or the shop's honorific for a customer's purchase, as in 「お買い上げ」.
• Synonym買い求めるかいもとめるWrittenWritten style for buying something you want, as in 「土産を買い求める」; carries a dignified tone.
• Synonym買い入れるかいいれるNeutralTo buy in for one's own use or stock, as in 「原料を買い入れる」; common for procuring supplies, unlike the plain act of 購入.
• Synonym買うかうNeutralThe everyday native verb for buying. 購入 is a Sino-Japanese word that sounds more formal and written, as in online-shopping instructions.
• Synonym買い取るかいとるNeutralTo buy something over into your ownership — used cars, land, rights, even firms, as in 「中古車を買い取る」. 購入 stresses the act of buying itself.
• Synonym購買こうばいWrittenWritten word for procurement, or the school co-op store in 「購買部」; 購入 is the ordinary formal word for buying.
• Synonym買いかいCasualColloquial noun for buying in, e.g. a stock's 「買い」; mostly finance jargon or in compounds.
• Synonym買い上げかいあげFormalFormal noun for buying up or purchase; today mostly the shop honorific 「お買い上げ」.
• Synonym買い付けるかいつけるNeutralBulk buying or buying regularly at a place; leans toward merchants procuring stock rather than the neutral act of 購入.
• Synonym買い受けるかいうけるWrittenWritten and legal-flavoured: buying under a contract, taking over goods or rights by purchase.
• Related買取かいとりNeutralNoun for buying over or buying up — used-goods trade-ins, land, shares, as in 「買取価格」. 購入 is the buyer's plain purchase.
• Related買収ばいしゅうFormalFormal: acquiring a company or bribing, as in 「企業買収」「票を買収する」; leans to takeovers, not everyday buying.
• Related買い物かいものNeutralEveryday shopping or errands, as in 「買い物に行く」; 購入 names the purchase itself, not the outing.
• Related買い付けかいつけNeutralNoun for bulk procurement on the business side, as in 「買い付け担当」; 購入 is the general word for buying.
• Related購求こうきゅうWrittenWritten word for buying or purchasing; rarely used today. In formal contexts the usual word is 「購入」.
• Related買い込みかいこみCasualColloquial noun for buying in bulk and stocking up; the noun counterpart of 買い込む.
• Related購うあがなうWrittenWritten, archaic verb for paying money to buy; rarely seen in modern Japanese.
• Antonym販売はんばいNeutralAntonym: selling and marketing — the seller's side of the deal that 購入 describes from the buyer's side.
• Antonym売却ばいきゃくWrittenWritten antonym: selling off assets such as property or a business — the reverse of 購入.

Use 「購入」 for formal or written talk of buying, as in 「チケットを購入する」. For everyday speech say 「買う」; stocking up is 「買い込む」; buying something over into your ownership is 「買い取る」; corporate takeovers are 「買収」. The opposites are 「販売」 and 「売却」.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. 物ものを買かうこと。