Very old worker hiding one hundred from Spain (7)
I believe the answer is:
ancient
'very old' is the definition.
(I've seen this before)
'one hundred from spain' is the wordplay.
'one' becomes 'an' (an apple is one apple).
'hundred' becomes 'c' (Roman numeral).
'from' says to put letters next to each other.
'spain' becomes 'ient' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'an'+'c'+'ient'='ANCIENT'
'worker hiding' is the link.
This may not be right. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for ancient that I've seen before include "Very old, like the poetic mariner" , "Early" , "Shakespearean standard-bearer" , "Historic standard" , "Old salt in Coleridge's poem" .)