different kanji with the same Japanese reading
Linguistic term for words that share a reading but are written with different kanji, often with related meanings. Compare 同訓異字, which is essentially synonymous.
See also: 同訓異字
"暑い" and "熱い" are examples of different kanji with the same Japanese reading.
Distinguishing between different kanji with the same reading is one of the difficult points for Japanese learners.