Very regularly catches fever, getting increasingly woozy (6)
I believe the answer is:
vaguer
'increasingly woozy' is the definition.
I can't tell whether this definition defines the answer.
'very regularly catches fever' is the wordplay.
'regularly' means one should take alternating letters (regularly take one letter, leave next etc.).
'catches' means one lot of letters goes inside another.
'fever' becomes 'ague' (I've seen this before).
The alternate letters of 'very' are 'vr'.
'vr' placed around 'ague' is 'VAGUER'.
'getting' is the link.
Can you help me to learn more?
(Other definitions for vaguer that I've seen before include "Less well defined" , "increasingly rough" .)