14D Secure way to tie string.
2 words 4 letters each word
I have R???? - KNOT
Thinking 'reef knot'
But throws out my 17A Measuring device
1 word 5 letters
???E?
I think;- RULER
Reef would mean replacing U in ruler with E
Leaving me ?E?E? Level? As in spirit level?
Reef knot would leave me