The present investigation deals with the study of higher-order nonlinearity and dispersion to electron-acoustic waves in an unmagnetized and collisionless plasma system incorporating immobile ions, cool adiabatic electrons and nonthermal-Tsallis distributed hot electrons. Employing proper stretched coordinates and Reductive Perturbation Method (RPM), dispersion relation and Korteweg de-Vries (KdV) equation have been derived to the lower-order potential. An inhomogeneous KdV-type equation emerges to the next higher order that accounts for fifth-order dispersion. This study focuses on revealing the dependency of the behaviour of dressed electron-acoustic waves on nonthermal parameter (β), hot-to-cool electron density ratio (α), hot-to-cool electron temperature ratio (θ), Mach number (ΔM\documentclass[12pt]{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsbsy}
\usepackage{mathrsfs}
\usepackage{upgreek}
\setlength{\oddsidemargin}{-69pt}
\begin{document}$${{\Delta} M}$$\end{document}) and nonextensive parameter (q). Only negative potential structures are reported for which the numerical results are interpreted in the form of two and three-dimensional profiles. The numerical results reflect the decrease in the amplitude of dressed solitary structures, thus obliging simulation of electron-acoustic solitary behaviour in the auroral regions and magnetosphere of Earth.
