1. Capable of being thought about
   "space flight to other galaxies becomes more cogitable"
   - ponderable

See also: thinkable

• letter box
• letter carrier
• letter case
• letter of credit
• letter of intent
• Letter of Jeremiah
• letter of mark and reprisal
• letter of marque
• letter of the alphabet
• letter opener
• letter paper
• letter security
• letter stock
• letter telegram
• letter writer
• letter-perfect
• lettercard
• lettered
• letterer
• letterhead
• lettering
• letterman
• letterpress
• letters
• letters of administration