The colony collapsed? George goes in for application of practical or mechanical science? (10)
I believe the answer is:
technology
'science?' is the definition.
(I know that technology is a type of applied science)
'the colony collapsed? george goes in' is the wordplay.
'collapsed?' indicates anagramming the letters.
'george' becomes 'g'.
'goes in' means one lot of letters goes inside another.
'the'+'colony'='thecolony'
'thecolony' with letters rearranged gives 'technoloy'.
'technoloy' going around 'g' is 'TECHNOLOGY'.
'for application of practical or mechanical' acts as a link.
This may not be correct. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for technology that I've seen before include "Practical sciences" , "Practical application of science" .)