noun

• An area of decayed vegetation (particularly sphagnum moss) which forms a wet spongy ground too soft for walking.
  "Bogs are acidic, nutrient poor, and have a low species diversity, whereas fens are less acidic and have higher nutrient levels and species diversity. Typically, the herbaceous layer in bogs is dominated by sphagnum moss, whereas[…]"
• An area of decayed vegetation (particularly sphagnum moss) which forms a wet spongy ground too soft for walking.
  "He laughed each time a camel sank down, and he laughed as they strained and pulled and struggled to get the beast on to its clumsy feet again. So sure on sand, so clumsy in bog!"
• (figuratively) Confusion, difficulty, or any other thing or place that impedes progress in the manner of such areas.
  "...quagmires and bogges of Romish superstition..."
• (UK, Ireland, Australia and New Zealand, slang) A place to defecate: originally specifically a latrine or outhouse but now used for any toilet.
  "I'm on the bog"

verb

• (transitive, now often with "down") To sink or submerge someone or something into bogland.
  "To be 'bogged down' or 'mired down' is to be mired, generally in the 'wet valleys' in the spring."
• (figuratively) To prevent or slow someone or something from making progress.
  "[…] Bogg'd in his filthy Lusts […]"
• (intransitive, now often with "down") To sink and stick in bogland.
  "Duncan Graham in Gartmore his horse bogged; that the deponent helped some others to take the horse out of the bogg."
• (figuratively) To be prevented or impeded from making progress, to become stuck.

noun

• (obsolete) Alternative form of bug: a bugbear, monster, or terror.

adj

• (obsolete) Bold; boastful; proud.
  "The Cuckooe, seeing him so bog, waxt also wondrous wroth."