Eco Dictionary game

Here are the rules.

You look up a word in a dictionary(or somewhere like http://www.dictionary.com) then put the definition here for people to guess what word it is. Please keep it on eco topics.

Here is the first one:

any of various machines having a rotor, usually with vanes or blades, driven by the pressure, momentum, or reactive thrust of a moving fluid, as steam, water, hot gases, or air, either occurring in the form of free jets or as a fluid passing through and entirely filling a housing around the rotor.

what do you think it is? 

Um, is it.... Turbine?

Here's my definition...

the branch of biology dealing with the relations and interactions between organisms and their environment, including other organisms.  

Can anyone guess it without looking anything up?

You didnt wait for me to tell if you if you were right or not but you are  

Oooops, sorry, I was a bit eager there! I had thought of a good one so wanted to get my definition in!

I'll wait to see if I'm right next time

Is it food web?

nope, sorry. I'll give you a little clue...

 It's considered a form of science and part of your name will help you...!

Is it Ecology ? Or Eco Science

 maybe pharmocologey? i spelt that wrong though...

 Could the answer be economics or habitat......

hmmmmmmm

 The answer is Ecology - well done Eco Warrior, it's your turn to pick something now.

I thought the definition of Ecology was interesting - 'interactions between organisms and their environment' - when you look at the changes in the wildflife because of the difference in seasons recently it's scary.

Thanks Kitty, heres mine:

The variety of living things in an environment

Good luck,

Biodiversity?

 That's what I was going to say! I'll let you have it if it's right though

My other guess would have been eco-system.

 Wow, photo-finish.

Footprint Friends just won it though by a nose.

Close second Kitty.

It was Bio-Diversity!

Your turn Footprints,

 Oh, rubbish! You're going to have to think of a really good one now Footprint Friends! Expectations are officially high!