Sound-loan for English 'index' coined in the 1930s by Yenching scholar 洪业 (William Hung) for the Harvard-Yenching Sinological Index Series. In modern usage, 索引 has largely replaced it. 引得 is now mostly historical/library-science terminology.
mistakes
Don't confuse with the verb phrase 引得 ('caused to') as in 引得大家哈哈大笑, that's 引 + the particle 得, not this loanword.
