きた鍛kitaえるeru
1.
To strengthen or improve the quality of a material or skill through repeated processes, such as heating and manipulating metal, or through rigorous training and practice.
2.
To develop one's body or abilities by enduring challenging training regimens, aimed at enhancing physical strength, technical skills, or mental resilience.
3.
To repeatedly undergo harsh training to achieve heightened performance or mastery in a particular area, such as sports or martial arts.
Example:
彼は鋼を鍛えて刀を作った。