use strict;
use warnings;
use 5.010;

my @strings = (
    'hello',
    'hello >knowled<ge< goodbye',
    'hello >knowledge< goodbye',
    'hello >!knowledge< goodbye',
);


for (@strings) {
    if ( />(.+)</ ) {

        my $word = $1;

        if ( $word =~ /^\w[^><]*$/ ) {
            say $word;
        }
    }
}

--output:--
knowledge


##</code><code>##

 if ( />(.+)/ and /(^\w+)</ ) {
    #...do something
}