The purpose of this quantitative study utilizing a quasi-experimental one-group pretest-posttest design was to improve the student’s vocabulary knowledge on lexical relations among high school students. The study participants were 30 eleventh-grade students from Asuncion National High School. The study introduced an intervention called WWW (Word Web Wonders) Intervention to improve student vocabulary knowledge. The pre-test and post-test results showed a significant difference: the pre-test had a mean score of 15.3 (SD = 3.08), while the post-test showed a mean score of 32.8 (SD = 4.28). The statistical analysis revealed a significant improvement in students’ vocabulary knowledge following the intervention, t (29) = 43.1, p < 0.001. The result found out that there was a difference between the pre-test and post-test based on its overall mean. Additionally, the effect size, as measured by Cohen’s d, was approximately 4.69, indicating an extremely large effect. These findings suggested that the intervention effectively improved students’ vocabulary knowledge levels. To provide a comprehensive understanding of the students' insights during and after the intervention, the researchers conducted interviews with selected individuals. From the responses gathered, five themes emerged regarding the insights of students: (1) Increased Vocabulary Retention and Understanding; (2) Increased Awareness of Different Word Relationships; (3) Using One’s Newly Acquired Vocabulary in Real Communication; (4) Increased Self-Efficacy and Confidence in Addressing Vocabulary Challenges; and (5) Activation of Prior Knowledge.