This is the 639th most frequent Russian word.
лидер
Leader.
Here, 'лидер' is used to describe a person who leads or is in charge of a group or team.
Этот спортсмен является лидером нашей команды.
This athlete is the leader of our team.
In this sentence, 'лидер' refers to the person or entity currently leading in a competition or race.
Лидер гонки увеличил своё преимущество.
The race leader increased their lead.
Here, 'лидер' is used metaphorically to mean an entity excelling or leading in a specific field or industry.