The kanji 練 primarily conveys the idea of "to practice," "to train," "to refine," or "to knead." It suggests a process of repeated action or effort to improve a skill, quality, or substance. It implies a transformation through repetitive action, leading to a polished or enhanced state.

・On-yomi (音読み): ⚫︎ レン (ren) ・Kun-yomi (訓読み): ⚫︎ ね（る） (neru) - to knead; to practice

⚫︎ 練習（れんしゅう） Translation: Practice; training. ⚫︎ 練乳（れんにゅう） Translation: Condensed milk. ⚫︎ 鍛練（たんれん） Translation: Training; discipline; tempering.

The kanji 練 is a phono-semantic compound (形声文字, keisei moji). ⚫︎ The phonetic component is 柬 (ken), which originally depicted a type of brush. ⚫︎ The semantic component is 糸 (ito), meaning "thread" or "silk". ⚫︎ Together, they suggest the idea of repeatedly manipulating or refining silk threads, like carding them or twisting them, which lead to the meaning of "to practice" or "to refine."