a
1
n
1
t
1
i
1
p
3
a
1
r
1
t
1
i
1
c
3
l
1
e
1
s
1
13 letters ·
17 points in Scrabble
Meaning
noun
a particle that has the same mass as another particle but has opposite values for its other properties; interaction of a particle and its antiparticle results in annihilation and the production of rad