I have solved my problem with another problem but closer to the solution awk 'cnt[$1]++{$1=$1"-\t"} {printf "%s\n", $0}')
Now I want to replace the old field
defining a new variable that contains the new labels using above awk one-liner renamed_column replacing it in awk -v v=$renamed_column '{$1=v; printf "%s%s\n", $1, $2}' <<< "$array1"