Meanings

stubborn (obstinate) father

firm and solid

fixed idea

of strict morals (moral principles)

being of firm (unshakable) faith and strict practice

very cautious (watchful, vigilant)

stiff consistency

endemic species

landline telephone

landline telephone

(penalty of) imprisonment

to coat a surface with something that adheres strongly when hardened (i.e. grout, plaster, lacquer)

fixed cost

fixed exchange rate system

semisolid

online handle (esp. on an online forum like 2ch where the majority of users post anonymously)

regular staff

obstinate

solid phase

firm