What word unites them?
A GRANMA ... ...
TO BE PAID .. . ..
MACHINE-LIKE . ... .
LIVE AGAIN (LINGUA MEA) .....
The uniting word is
RAINBOW!!!
Because
Each of these clue a different 7 character word:
1. A GRANMA = anagram of 'ANAGRAM'
2. TO BE PAID = 'PAYABLE'
3. MACHINE-LIKE = 'ROBOTIC'
4. LIVE AGAIN (LINGUA MEA) = latin for revive = ‘REDIVIV’
Giving this squaare:
ANAGRAM
PAYABLE
ROBOTIC
REDIVIV
Now
If we compare these to the dots and consider the letters where there are no dots, we get:
G
Y B
O I
R V
This is
ROYGBIV - the colours of the rainbow, in the shape of a bow!
In fact, treating the dots as raindrops, it literally forms a bow in the rain!
So the uniting word is
RAINBOW!!!