The most common and most likely answer to this crossword clue is the 6 letter word STERNA
S
T
E
R
N
A
More clues leading to the result STERNA
- More rigid articulated bones
- Bones in back area
- Bones of saint — any number gathered in time
- Bones in back start to ache
- Bones more rigid, did you say?
- d Zhivago’s man, missing dad, initially keeps bones
- Bones harder, by the sound of it?
- What should come with ribs — portion of Harvester nachos?
- Inflexible adult bones
- Bones are hard with adults
Buddy explains!

The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does STERNA mean?
STERNA noun- The breastbone
- The sclerotized plate of spiders, between the coxae, marking the floor of the cephalothorax