# If you'd like to omit non-matching lines from the result; add ';d' to the end of the expression.
sed -E 's/(?:(ST)REET|(AVE)NUE|(B)OU(L)E(V)AR(D))/\1\2\3\4\5\6/g;t' <<< "I live on 56 something STREET
I live on 56 something AVENUE
I live on 56 something BOULEVARD
"
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for SED, please visit: https://www.gnu.org/software/sed/manual/html_node/The-_0022s_0022-Command.html