This is the 12067th most frequent Spanish word.
injustificado
Unjustified; lacking justification or reason.
Here, 'injustificado' is again an adjective, providing a characterization of the 'queja' (complaint) as being unwarranted due to its lack of basis in fact.
Su queja era injustificada porque no revisó bien los hechos.
His complaint was unjustified because he didn't review the facts properly.
In this example, 'injustificada' is describing the manner of the attack, indicating that there was no justification for the peers' behavior.
Se sintió atacado de manera injustificada por sus compañeros.
He felt unjustifiably attacked by his peers.
In this sentence, 'injustificado' is used as an adjective to describe a punishment as lacking a valid reason or fairness.