Definition of "gi"

By the time they got up to the reception building, there was a welcoming committee standing in the lamp-lined drive, all in black gi, headed by a tall, fit, scholarly-looking woman named Sister Rochelle […]

1990, Thomas Pynchon, Vineland, Vintage, published 2000, page 108

Attenders watched the Mad Max: Fury Road star, dressed in a blue gi, subdue his opponents and win all his matches. Hardy’s certificate of achievement was awarded to “Edward Hardy” – the actor’s real name.

2022 September 20, Danya Hajjaji, “‘Really nice guy’: Tom Hardy surprises competitors with entry and victory in martial arts contest”, in The Guardian‎