Both are adjectives;
Sensual:
"Connected with your physical feelings; giving pleasure to your physical senses." (OALD) the origin is from Latin sensulis, from sensus 'faculty of feeling, thought, meaning', from sentire 'feel'.
Sensuous:
"Giving pleasure to your senses." (OALD) the origin is from Latin sensus 'sense'+ous.
Here are two examples:
"The sensual feel of a velvet shirt against the skin."(Merriam Webster)
"The sensuous feeling of silk on her skin." (Longman Dictionary)
I wonder if "sensual" and "sensuous" can be interchangeable or there is a subtle difference.
Best Answer
The terms technically resemble each other, but in my experience, "sensuous" is a less excitable term and refers to information taken in through the senses; whereas "sensual" is more provocative, even suggestive. The latter would be more pleasurable as a rule. Here's a note from my computer dictionary (New Oxford American):
Perhaps, "Our day at the spa was exceedingly sensuous" vs "Her whisper in my ear was so sensual I could hardly take a breath."