The third letter starts the next word

[tinytn]

Underground

D

 

[hollydolly]

Defined

F

 

[Tish]

Family

M

 

[hollydolly]

Mask

S

 

[Owlivia]

Shore

O

 

[hollydolly]

Opium

P

 

[Tish]

Prince

I

 

[hollydolly]

Image

A

 

[Tish]

Arrow

R

 

[tinytn]

Radio

S

 

[hollydolly]

Radio

S

third letter ^^^

D

Drain

A

 

[jeff]

Dragon
A

 

[hollydolly]

Annuity

N

 

[*poppy*]

Never

V

 

[hollydolly]

Vole

L

 

[Owlivia]

Listless

S

 

[hollydolly]

Sponge

O

 

[Tish]

Open

E

 

[tinytn]

Engine

G

 

[hollydolly]

Graph

A

 

[*poppy*]

Aspire

P

 

[hollydolly]

Perimeter

R

 

[jeff]

Razor
Z

 

[hollydolly]

Zephyr

P

 

[*poppy*]

Puzzle

Z