impalpable /im-palˈpə-bl/

1. Not perceivable or detectable by touch
2. Not capable of being comprehended or grasped
3. Extremely fine-grained

impalpabilˈity noun

• billboards
• billbook
• billbooks
• bill-broker
• bill-brokers
• bill-chamber
• bill-chambers
• bill-discounter
• bill-discounters
• -billed
• billed
• billet
• billet-doux
• billeted
• billet-head
• billet-heads
• billeting
• billets
• billets-doux
• billfish
• billfishes
• billfold
• billfolds
• billhead
• billheads