一心(いっしん)

いっしん
noun, adverb
wholeheartedness, single-mindedness
cognitionemotion
1. wholeheartedness, single-mindedness, concentration
The state of devoting one's entire mind and energy to a single purpose, without distraction.
一心(いっしん)に勉強(べんきょう)する。
To study wholeheartedly.
合格(ごうかく)を目指(めざ)して一心(いっしん)に努力(どりょく)した。
I worked single-mindedly toward passing the exam.
彼(かれ)は一心不乱(いっしんふらん)に本(ほん)を読(よ)んでいた。
He was reading a book with total, undivided concentration.

Usage

Most commonly used in the adverbial form 一心(いっしん)に, meaning "wholeheartedly" or "with single-minded devotion."
一心不乱(いっしんふらん) is a four-character compound (四字熟語(よじじゅくご)) originally from Buddhism, meaning to be so focused that nothing can disturb one's concentration.

Common collocations

  • 一心(いっしん)に: wholeheartedly, with all one's heart
  • 一心不乱(いっしんふらん): with complete concentration, with undivided attention
  • 一心同体(いっしんどうたい): of one mind and body (used for very close relationships)

Related Words

Antonym: 二心(ふたごころ) (duplicity, disloyalty)
Synonym: ひたすら (single-mindedly, earnestly)
Compare: 一途(いちず) (wholehearted)
general
Added 2026.2.15 18:12 · Revised 2026.9.2 13:01
11000/11236_isshin