For a weapon:
* धनुष (dhanush) - This is the most common word for a bow used as a weapon.
For a gesture of respect:
* प्रणाम (pranam) - This word refers to a bow or a salutation made with the head or hands.
* नमन (naman) - This also means bow or a gesture of respect.
For a knot in a ribbon:
* धनुष (dhanush) - This can also be used for a bow in the context of a ribbon.
For a rainbow:
* इंद्रधनुष (indradhanush) - This word means rainbow, which is sometimes referred to as a "bow in the sky."
The specific word you need will depend on the context in which you are using "bow."