What word can fulfill the most parts of speech?

I know there are several parts of speech:

• Noun
• Verb
• Pronoun
• Adjective
• Adverb
• Preposition
• Conjunction
• Interjection

There might be others as well. Sometimes a word, depending on how it is used, can fulfill more than one of these classes. For example, the word "run" can be a verb:

I run fast.

or it can be a noun:

Let's go for a run!

What word, taking into account all its definitions, can fulfill the most word classes?

Well is an interjection, adjective, adverb, noun, and verb. That's five.

Business is going well. [adverb]
All is well with us. [adjective]
Well, who would have thought he could do it? [interjection]
The well was drilled fifty meters deep. [noun]
Tears well up in my eyes. [verb]

There's also round, with five, if you count when it is used to mean around:

Give me a round figure. [adjective]
Shall we play another round of cards? [noun]
He had a look round before he kept going. [adverb]
They walked round the tree. [preposition]
The floor function rounds down. [verb]

Damn fits five of the categories.

-a verb: Damn you!

-a noun: I don't give a damn.

-an adjective: The damn rain won't stop.

-an adverb: That was damn close.

-an interjection: Damn! That was close.

The OED has definitions for but as 6 parts of speech: conjunction, preposition, adverb, noun, verb, adjective and pronoun.

• conjunction - "I would go to the store, but it's raining".
• preposition - "everything but the dog"
• adverb - "Bring but a bottle o' Primrose wine" (from OED) (synonymous with 'only')
• noun (archaic or Scots dialect) - "I found him settled in this but and ben." (OED) (inside of a house)
• verb - "Nay, but me no buts" (OED)
• adjective - "He conducted me to the but end of the mansion." (OED) (the very end)
• pronoun - "Not a man but felt the terror in his hair." (OED) sort of a negative 'who'

How about the word down?

• Noun: His pillow is made of down.
• Verb: The quarterback downed the ball.
• Preposition: He lives down the street.
• Adjective: His coat is made of down feathers.
• Adverb: He fell down.
• Interjection: Down, Fido!