IPA: /ˈpræktɪsɪŋ/
KK: /ˈpræktɪsɪŋ/
Someone who is actively involved in a particular profession or way of life, such as a lawyer or a member of a religion.
She is a practicing doctor who helps many patients every day.
Comparative: more practicing
Superlative: most practicing
Practicing → It is formed from "practicus" (from Greek "praktikos", meaning active or practical) and the suffix "-ing" (indicating the action or process of). The word "practicing" refers to the action of actively engaging in a skill or activity to improve proficiency.
Think of being 'active' ('practicus') in doing something repeatedly — that's why practicing means actively working on a skill.