(いっしん)

いっしん
noun, adverb
wholeheartedness, single-mindedness
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)勉強(べんきょう)する。
To study wholeheartedly.
合格(ごうかく)目指(めざ)して一心(いっしん)努力(どりょく)した。
I worked single-mindedly toward passing the exam.
(かれ)一心不乱(いっしんふらん)(ほん)()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."

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)

NOTE:
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.