noun

• A substance composed of a large collection of bubbles or their solidified remains, especially:
  "Similarly, the biotech giant Cargill has begun manufacturing a polymer from vegetable oils that is used in polyurethane foams, which is found in beddings, furniture and car-seat headrests."
• A substance composed of a large collection of bubbles or their solidified remains, especially:
• (figuratively, poetic) The sea.
  "He is in Europe, across the foam."
• (African-American Vernacular, in the plural) Sneakers.

verb

• (intransitive) To form or emit foam.
  "[…] And that is it Hath made me rig my navy; at whose burthen The anger'd ocean foams; with which I meant To scourge the ingratitude that despiteful Rome Cast on my noble father."
• (intransitive) To spew saliva as foam; to foam at the mouth.
  "[…] to London will we march amain, And once again bestride our foaming steeds, And once again cry ‘Charge upon our foes!’ But never once again turn back and fly."
• (firefighting) To coat or cover with foam.
  "It used to be common practice to foam the runway prior to an emergency landing, in case a fuel-fed fire occurred."