12-Letter Words Matching ________TR__

There are 34 12-letter words that match ________TR__. 6 are common words, such as ETHNOCENTRIC and HELIOCENTRIC. A rarer one is TENSIOMETRIC. 6 words contain a doubled letter.

Full list 34

Common words

ethnocentricheliocentricreconnoitredreconnoitresthermometricweatherstripchronometriccolorimetricdorsiventraldorsoventralergonometricfissirostral
ethnocentricheliocentricreconnoitredreconnoitresthermometricweatherstripchronometriccolorimetricdorsiventraldorsoventralergonometricfissirostralisodiametricphotoneutronpsychometricpyroelectricactinometricamperometricandrocentricantielectronaxisymmetriccalorimetriccatadioptriccyclodextrindilatometricdissymmetricdynamometricfluorimetricfluorometricmorphometricnonsymmetricpolarimetricseismometrictensiometric

About this list

Words
34 (6 common words)
Common example
ethnocentric
Rare example
tensiometric
Doubled letters
6
Ending in S
1

Questions

How many 12-letter words matching ________tr__ are there?

34. 6 of them are common words.

What is a common example?

ETHNOCENTRIC is among the common words in this set.