godan ~す verb / transitive:

• to take down (e.g. flag); to launch (e.g. boat); to drop; to lower (e.g. ladder); to let (a person) off; to unload; to discharge
• to drop off (a passenger from a vehicle); to let (a person) off
• to withdraw (cash)
• to wear (clothing) for the first time
• to fillet (e.g. a fish)

godan ~く verb / intransitive verb / transitive:

• to open; to undo; to unseal; to unpack
• to bloom; to unfold; to spread out
• to open (for business, e.g. in the morning)
• to be wide (gap, etc.); to widen

godan ~く verb / transitive:

• to hold (meeting, etc.); to give; to open
• to found (nation, dynasty, sect, etc.); to open (a new business); to set up; to establish; to start
• to open (ports, borders, etc.)
• to open (an account)
• to open up (new land, path, etc.); to clear; to develop ➜ 拓く
• to open (a file, etc.) - IT term
• to extract (root); to reduce (equation) - Mathematics term
• to cut open (fish) - as 魚を開く - Food term
• to change (kanji into hiragana)

godan ~く verb / intransitive verb:

• to flare (e.g. skirt)
• to slacken (into a poor posture) - as 体が開く, 肩が開く, etc. - Sports term

noun:

• muscle; tendon; sinew
• vein; artery
• fiber; fibre; string
• line; stripe; streak
• reason; logic ➜ 筋が通る
• plot; storyline
• lineage; descent
• school (e.g. of scholarship or arts)
• aptitude; talent
• source (of information, etc.); circle; channel
• well-informed person (in a transaction)
• logical move (in go, shogi, etc.)
• ninth vertical line - Shōgi term
• seam on a helmet
• gristly fish paste (made of muscle, tendons, skin, etc.) - abbreviation ➜ 筋蒲鉾
• social position; status - archaism

suffix noun / noun / ~の noun:

• on (a river, road, etc.); along

suffix / counter:

• counter for long thin things; counter for roads or blocks when giving directions
• (Edo period) counter for hundreds of mon (obsolete unit of currency) - archaism