A worsted is a bit finer than an Aran, heavier than a DK.
Knitting with worsted normally gives 20 stitches per 10 cm/4in in stocking stitch. Aran would give 18, DK 22.
With crochet, the hook size and stitch type will make a huge difference. If you use the stated hook with a worsted instead of an Aran weight you’ll have a more open fabric. That may be what you want, especially with a cotton.
Best advice to give is to do a sample of at least 15 by 15 cm / 6 x 6 inches. That will give you a benchmark of the stitch size, the amount of yarn used and the stiffness or drape of the fabric you’re creating.
Google is wrong. Aran is a thicker yarn on average. Worsted is between DK and Aran.
Here’s just the top of the yarn menu from Canada’s largest wool independent store. Wool-Tyme. As we get EU, and UK yarn as well as US, the full range is represented.
Suggest that the OP look through their sizes to see what UK yarns fall under ‘worsted.’
https://wool-tyme.com/collections/yarn