Codenames 31

[El Grillo]

Fainting SPELL for sure.
'PASSing out' is a synonym for Fainting.
Fainting could be a symptom of a DISEASE requiring a NURSE's care.

Maybe our spymaster saw the NURSE+DISEASE pair and wanted a third word to go with them?

[Azoth]

A number of connections, none of them especially strong:

"Fainting SPELL" is an old-fashioned phrase
You can turn GREEN from sickness/nausea, though fainting is more closely associated with turning white/pale
Fainting could be a sign of underlying DISEASE
"PASSing out" is a modern colloquialism
There is a cliche of women fainting at the sight of a MOUSE
Or you could faint because you've had one BOTTLE too many
Fainting could require the attentions of a NURSE

Of these, NURSE is safest. "PASSing out" is probably a better bet than "fainting SPELL". I don't have a good sense for the third word.

[Lewwyn]

Fainting SPELL
DISEASE might make you faint
Might need a NURSE

Fainting is to PASS out

[sunrise089]

Agree with Lewwyn. Point to Spell
Point to Disease
Point to Nurse

[WarriorKnight]

SPELL is red
DISEASE is red
NURSE is grey

BATTERY	BRUSH	SPELL	PIANO	SOLDIER
GREEN	ROUND	DISEASE	POLE	TURKEY
PASS	HORSE	BILL	CHOCOLATE	MOUSE
SOUND	BELL	DATE	BOTTLE	JAM
THUMB	NURSE	SNOW	DOG	CAR

Grooming 3

[Bobchillingworth]

Dog
Brush
Horse or Date

[DaveV]

You groom a HORSE or a DOG, using a BRUSH. Convince me otherwise.

[JR4]

BRUSH looks pretty obvious here. Also, you can groom a HORSE and a DOG. I slightly prefer HORSE over DOG.

I could also see DATE as in preparing for a night out.

[Commodore]

Brush, natch
Horse, natch
So...Dog would then follow. At least I don't think it would be Red.

[Commodore]

Point to BRUSH
Bob/Dave, you guys feel dog is before horse? A horse-tender is called a groom, which is why I thought of it more clearly than dog.