Standard transliteration of 'Keith' — a common Anglophone given name. Famous bearers in Chinese subtitle data: Keith Richards 基思·理查兹 (Rolling Stones guitarist) and country star Keith Urban 基思·厄本.
usage
Each character is purely phonetic: 基 'kee', 思 'th'. The voiceless English 'th' becomes 思 by approximation. Don't read meaning into them.