Around week 7 of pregnancy, it's called this; after, it's a fetus
Embryo
No joke! Just 10 to 15 minutes of doing this a day can burn up to 40 calories according to studies.
Laughing
Nasus
Nose
Usually comes before "response", it describes how your body fends off viruses & bacteria
Immune
This FPS is a sub-genre of video games
First-person shooter
It's the lightest stable subatomic particle (that we know about)
Electron
It's the 2-word family relationship you have with the child of your mom's brother
First cousin
Pulmo
Lungs
Add a "B" to the end of a heroic word & you get this excellent follow-up!
Superb!
This FPS describes the frequency at which consecutive images are captured or displayed.
Frames per second
Langerhans cells are found in this layer of the skin
Epidermis
To libel or slander (but it doesn't mean to make less well known)
Defame
Bracchium
Arms
It sounds like an adverb, but it means expensive, or resulting in terrible harm
Costly
This FPS is a nuclear power system that uses the energy derived from splitting radioactive atoms.
Fission power system
These hormones relieve pain but probably don't give the runner's high as once thought
Endorphins
It's the playful response to "are too!"
Am not!
Auris
Ear
Lie down, look up & tell us of this opposite of prone
Supine
Daily Double!
This FPS is an Imperial system of units named from three fundamental units of measurement corresponding to length, mass, and time respectively.
The Foot-pound-second system
It's hibernation, but in summer
Estivation
It's where a river's mouth meets the ocean
Estuary
Genu (as in genuflect)
Knee
Of or relating to gods, it can also mean something excellent or delightful
Divine
This FPS in telecommunications is a variant of packet switching that increases data transmission by bypassing some error-checking protocols.
Fast packet switching