•The newly compound 2-(1-(3-methyl-1-oxo-1,2,3,4-tetrahydronaphthalen-2-yl)ethyl)malononitrile was successfully synthesized.•The newly synthesized compound was characterized using FT-IR, 1H NMR, 13C NMR, elemental analysis, Mass spectrometry, and XRD studies.•The antioxidant capacity of the synthesized compound was scrutinized in-vitro by three methods.•Molecular docking studies of the compound was performed towards four antioxidant proteins (1N8Q, 1OG5, 2CDU, and 4JK4). In the current study, we report the synthesis, structural determination, and both in vitro and in silico antioxidant assessment of 2-(1-(3-methyl-1-oxo-1,2,3,4-tetrahydronaphthalen-2-yl)ethyl)malononitrile. The title compound was synthesized via the 1,4-Michael addition reaction of malononitrile with (E)-2-ethylidene-3-methyl-3,4-dihydronaphthalen-1(2H)-one in the presence of piperidine. The molecular structure of the synthesized compound was elucidated using various techniques such as 1H NMR, 13C NMR, IR, elementary analysis (AE) and confirmed by mass spectrometry (MS), as well as by the X-ray diffraction (XRD) analysis. Notably, the XRD study showed the investigated compound crystallizes in the triclinic system (S.G.: P-1). The target compound was evaluated for its antioxidant ability employing the Free radical scavenging (DPPH), Ferric reducing power (FRAP), and Phosphomolybdenum (PM) tests. The findings revealed that the compound displays an interesting antioxidant power. Furthermore, the molecular docking results show that the studied compound has a potential antioxidant effect, producing stable intermolecular interactions towards antioxidant proteins encoded in the protein data bank (PDB) by 1N8Q, 1OG5, 2CDU, and 4JK4, respectively. Display omitted