part of part of gonad embryonic structure indifferent gonad A gonad prior to differentiating into a definitive testis or ovary. EHDAA2:0000716 UBERON:0009117 UMLS:C1512703 gonad rudiment typically part of the embryo - however, in male tammar wallabies the gonads are indifferent at the neonatal stage[8827321] uberon indifferent external genitalia