BROMOURACIL

ˌbrōmōˈyu̇rəˌsil, -məˈ-, -_sə̇l noun

Etymology: brom- + uracil

: a mutagenic uracil derivative C 4 H 3 N 2 O 2 Br that is an analogue of thymine and pairs readily with adenine and sometimes with guanine during bacterial or phage DNA synthesis