拡大|かくだいkakudai[0]heiban (flat)

1. noun, suru verb, transitive verb, intransitive verbexpansion; extension
   今年ことしは事業じぎょうが５０％拡大かくだいした。↗

   The business has expanded by 50% this year.
2. noun, suru verb, transitive verb, intransitive verbmagnification; enlargement
   この顕微鏡けんびきょうは物ものを１００倍ばいに拡大かくだいする。↗

   This microscope magnifies objects by 100 times.
3. noun, suru verb, transitive verb, intransitive verbescalation; spread

• Synonym広がるひろがるNeutralIntransitive: a range grows or spreads, as in 「火が広がる」. Common in everyday speech; 「拡大」 is a Sino-Japanese word mostly for scale and figures.
• Synonym拡張かくちょうWrittenWritten word for extending territory or roads, or adding functions, as in 「拡張機能」; 「拡大」 is about scale or scope getting bigger.
• Synonym伸長しんちょうWrittenWritten style: growth in length or influence, as in 「売上の伸長」; stresses how much something has grown.
• Synonym広げるひろげるNeutralTransitive: to spread something out or widen it, as in 「事業を広げる」「地図を広げる」; more colloquial than 「拡大」.
• Synonym広まるひろまるNeutralIntransitive: news or practices spread and catch on, as in 「噂が広まる」; about rumors and trends circulating, not scale.
• Synonym伸びるのびるNeutralTo lengthen or grow, as in 「背が伸びる」「記録が伸びる」; stresses length or figures moving upward.
• Synonym広めるひろめるNeutralEveryday transitive: to spread or popularize something, as in 「噂を広める」「知識を広める」; 「拡大」 is not used for spreading news.
• Synonym拡散かくさんNeutralTo scatter in all directions, as in 「情報が拡散する」; also sharing or reposting online, while 「拡大」 is about scale.
• Synonym発展はってんNeutralDevelopment to a higher stage, as in 「経済発展」; implies qualitative improvement, while 「拡大」 only says something gets bigger.
• Synonym拡充かくじゅうWrittenWritten word for expanding and enriching facilities or systems, as in 「施設を拡充する」; adds a nuance of enrichment 「拡大」 lacks.
• Synonym増大ぞうだいWrittenWritten word for growth in quantity or degree, as in 「負担が増大する」; mostly abstract amounts, while 「拡大」 is about scope.
• Synonym伝播でんぱWrittenWritten, academic word for the transmission of culture or waves, as in 「文化の伝播」; close to 「拡大」 only in the sense of spreading.
• Synonym広がりひろがりNeutralA noun for the extent or span something spreads over, as in 「空の広がり」; a state, while 「拡大」 is the act of growing.
• Synonym増すますNeutralNative verb for quantity or degree rising, as in 「水かさが増す」; about amount, while 「拡大」 is about scope.
• Synonym膨張ぼうちょうWrittenWritten word for swelling in volume, also figurative for budgets or cities growing, as in 「予算が膨張する」; often implies excess.
• Synonym押し広げるおしひろげるWrittenWritten: to force something open or push it over a wider area, as in 「傷口を押し広げる」; 「拡大」 does not stress physical force.
• Synonym伸展しんてんWrittenWritten style: extending influence or scale; rare, and everyday speech prefers 「拡大」 or 「伸びる」.
• Synonym伸べ広げるのべひろげるWrittenWritten: to stretch something out flat; very rare, and daily speech uses 「広げる」.
• Synonym取り広げるとりひろげるWrittenWritten: to spread out or enlarge; very rare, and daily speech uses 「広げる」 or 「拡大する」.
• Related展開てんかいNeutralTo unfold or develop, as in 「事業を展開する」「話の展開」; stresses the unfolding process, while 「拡大」 stresses getting bigger.
• Related延長えんちょうNeutralTo lengthen time or distance, as in 「延長戦」; about length and deadlines, while 「拡大」 is about scale and area.
• Related増加ぞうかNeutralAn increase in quantity, as in 「人口が増加する」; about numbers, while 「拡大」 is about scale and scope.
• Related普及ふきゅうNeutralReaching the general public, as in 「スマホの普及」; stresses widespread use, while 「拡大」 stresses scale.
• Related増殖ぞうしょくWrittenWritten word for the multiplication of cells or organisms, as in 「細胞が増殖する」; also figurative for multiplying manyfold.
• Related繰り広げるくりひろげるWrittenWritten: to unfold scene after scene, as in 「熱戦を繰り広げる」; does not mean scale grows.
• Related展延てんえんWrittenTechnical written term for rolling and flattening material, mainly metals; not used in daily life, and only superficially close to 「拡大」.
• Related伝搬でんぱんWrittenWritten: propagation of radio waves or signals, mostly in physics; close to 「拡大」 only in the sense of range extending.
• Antonym縮小しゅくしょうNeutralThe direct opposite: scale or scope shrinks, as in 「規模を縮小する」; also used for shrinking images.
• Antonym縮減しゅくげんWrittenWritten-style opposite: cutting quantities or spending, as in 「予算の縮減」.

Default to 「拡大」 for expansion. In everyday speech use 「広がる」 or 「広げる」; for adding functions or extending territory use 「拡張」, for expanding and enriching facilities use 「拡充」; for rising numbers use 「増加」; for news or rumors spreading use 「広まる」. The opposite of 「拡大」 is 「縮小」.

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

1. 規模きぼ・範囲はんいを広ひろげて大おおきくすること。また、広ひろがって大おおきくなること。
2. 写真しゃしん・映像えいぞうなどを引き伸ひきのばして大おおきくすること。