The code renders correctly neither on Firefox (desktop) nor mobile (some webview browser). It goes out of the screen both left and right.

Here it is since paragraph selection (triple click) doesn't exist in tap form on mobile. Added a few newlines because why not.

    pickaword() {
        WORDFREQFILE=/home/mywords.txt;
        WORDLENGTH=$1;
        FREQSUM=$(awk -v wordlength="$WORDLENGTH" 'length($1) == wordlength {s+=$2}END{print s}' "$WORDFREQFILE");
        CHOICE=$(shuf -i 0-$FREQSUM -n 1);
        awk -v wordlength="$WORDLENGTH" 'length($1) == wordlength {sum += $2; print $1, $2, sum} END {print sum}' "$WORDFREQFILE" | awk -v threshold="$CHOICE" '$3 < threshold' | tail -2 | head -1 | cut -f1 -d' ';
    }

If you just want to generate random words (I use this from time to time) (note: do not use for cryptographic purposes!), you can just do `shuf /usr/share/dict/words | head -1` on most linux systems (since most have a dictionary installed; else you might have to apt install wamerican or something), but of course that doesn't take language frequency into account like OP has. To select a word length you could do `grep ^....$ /usr/share/dict/words | shuf | head -1` with the number of dots being the number of characters.