3 letters

@handyandy said
It's medication for anxiety.

Looking through hefty dictionaries?
It was quite a calming activity.

@forkedknight said
Bingo? I did a google search, and found a couple of obscure chemistry papers that use "oxyxylene", and your post. I don't think oxyzylene is a thing

There's quite a few mentions of oxyxylene now (growing too).
Seems to recently have become a "thing".

RWR

@handyandy said
RWR

oveRWRought.

NXI

@orangutan said
NXI

anxiety

RSU

@handyandy said
anxiety

RSU

pursue

CTU

@wolfe63 said
pursue

CTU

rectum

DZO

@forkedknight said
rectum

DZO

GaDZOoks

RJE

@orangutan said
GaDZOoks

RJE

At last!
waterjet

KEK

@wolfgang59 said
At last!
waterjet

KEK

And the answer is pukeko a bird native to NZ & Australia.

SKM

@wolfgang59 said
SKM

taskmaster

BNE

@handyandy said
taskmaster

BNE

Subnet ! (just had to change one).

TCA

Fruitcake?

VYW

@iamatiger said
VYW

heavyweight

CCY

@handyandy said
heavyweight

CCY

coccyx

NFO