noun
wandering lordless samurai
Historical term for a masterless samurai (ronin) who wanders without a fixed lord or residence. The 天竺 (India) element is metaphorical, suggesting a far-off, exotic wandering, not literal travel to India.
戦国の世には、天竺浪人となって諸国を渡り歩く武士も少なくなかった。
In the Warring States period, not a few warriors became wandering lordless samurai and roamed the provinces.
浪人 is the general term for a masterless samurai; 天竺浪人 specifically emphasizes the wandering, rootless aspect with a metaphorical flourish.
Compound of 天竺 (India, used metaphorically for a faraway, exotic place) and 浪人 (masterless samurai). The exact origin of the metaphorical use is uncertain, but it evokes the image of a samurai wandering as if in distant lands.