Definitions:

1. connected by participation or association or use adjective
   • we accomplished nothing, simply because of the large number of people involved
2. entangled or hindered as if e.g. in mire adjective
   • the difficulties in which the question is involved
3. enveloped adjective
   • a castle involved in mist

Synonyms:

• Byzantine
• convoluted
• knotty
• mired
• tangled
• tortuous